A variety of products are available to consumers to aid in improving skin appearance, and in particular minimizing the visibility of discontinuities in skin appearance. One way to accomplish this is through the use of compositions including colored pigments. For example, cosmetic foundations (either in powdered or lotion form) contain colored pigments that are intended to mimic the skin's natural color. A problem with foundations of this type is that if such foundations are applied in a localized manner (e.g. only in a selected area of redness) the difference between the foundation color and the surrounding natural skin color may be readily apparent resulting in an irregular skin appearance. Alternatively, if such foundations are applied in a continuous manner over a larger area of skin, to thereby provide a more uniform skin appearance, an artificial “mask-like” appearance may result. It is further noted that in order to effectively conceal skin discontinuities, foundations of the type described above require relatively high pigment contents, which further contribute to the undesirable “mask-like” qualities of such compositions.
Certain colored lotions known in the art are specifically intended to reduce “redness”, that is reduce the red appearance of certain skin discontinuities. These redness reduction lotions typically rely upon classic pigments or dyes that appear green (the complementary color of red) to thereby deliver the redness reduction effect. The problem with such redness reduction lotions is that they can impart an unnatural green color to the healthy skin surrounding the skin discontinuity.
Efforts have been made to overcome the shortcomings of the products described above by way of personal care compositions that utilize interference pigments, in lieu of conventional pigments. Interference pigments typically are thin plate-like, colorless, particles including two or more layers. The layers of the interference pigment have different refractive indices, and reflect a color resulting from the constructive or destructive interference of reflections of light from the different layers.
A specific skin care composition including interference pigments is disclosed in US Patent Publication 2007065381A to Elsbrock, et al. Elsbrock discloses a skin care composition that includes a first pigment that reflects a first color and a second pigment that reflects a second complementary color.
The inventors of the present invention have discovered that one drawback of the composition disclosed in Elsbrock et al. is that a formulator making a composition in accordance with the teachings of Elsbrock et al. is limited in the selection of interference pigments that may be employed. Specifically, since the composition of Elsbrock et al. requires the use of a combination of a first and a second pigment that are complementary colors, a formulator is thus limited in the selection of interference pigments that may be employed. In addition, the inventors of the present invention have discovered that if redness reduction is desired, using a composition of the type disclosed in Elsbrock et al., may require the use of relatively high total pigment concentrations. Finally, the inventors of the present invention have discovered that since the composition of Elsbrock et al. require the use of a combination of a first and second pigment that reflect complementary colors, if the chroma of the composition is to be minimized the first and second pigments must be employed in a 1:1 ratio or substantially similar ratio.
In view of the above, the inventors have recognized that further improvements in skin care compositions including interference pigments are required. More specifically, the inventors of the present invention have recognized the need for compositions that minimize the red appearance of certain skin discontinuities with minimal impact on the appearance of the healthy skin surrounding the skin discontinuity. The inventors of present invention have also recognized the need for skin care compositions including interference pigments that can effectively reduce the red appearance of certain skin discontinuities at low total pigment concentrations. Finally, the inventors of the present invention have recognized the need for skin care compositions including at least a first and second interference pigment that have a relatively low chroma over a wide range of first and second pigment ratios.